Category: GE

FEATURES • Protections: – Transformer Percent Differential  (87T) – Instantaneous Differential (87/50) – Restricted Ground Fault (87G) – Overexcitation – Volts/Hz (24) – Phase/Neutral/Ground TOCs (51P, 51N, 51G) – Phase/Neutral/Ground IOCs (50P, 50N, 50G) – Phase and Neutral directional OC (67P, 67N) – Phase under- and over-voltage (27P, 59P) – Auxiliary under- and over-voltage (27X, 59X) – Neutral over-voltage (59N) – FlexElements – universal comparator • Controls: – Six Setting Groups – Under- and Over – frequency – Digital Elements – Digital Counters – Selector Switch – Synchcheck (optional) • Inputs/Outputs – Contact Inputs and Outputs – Virtual Inputs and Outputs – Direct Inputs and Outputs – Remote Inputs and Outputs(GOOSE)

INTRODUCTION Introduction: Multifunctional digital relay for transformer protection: • Configurable multi-protection transformer package • Up to 4 sets of CTs and/or VTs (T60) – Optional 5/6 windings • Up to 6 sets of CTs and/or VTs (T35) • Programmable FlexLogic • GOOSE and Direct I/O messaging • Easy access through HMI(Human Machine Interface) • Easy for monitoring and control PC program • Varieties of communications • Metering and Monitoring: – Currents(phasors and true RMS) – phase, ground, neutral, symmetrical components and demand – Voltages(phasors and true RMS) – phase, ground, neutral and symmetrical components – Power – active, reactive, apparent, power factor – Energy and energy demand – Per-phase differential and restraint currents – Ground differential and restraint currents – Per-phase 2-nd and 5-th harmonics on differential currents – 2-nd to 25-th harmonics currents and THD – Oscillography – Event Recorder – Data Logger – One PMU Element

Applications • Medium to large generators typically driven by steam, gas, or hydraulic turbines • Pumped storage generators used as pumping motors for reservoir storage • Stand-alone protection or component in automated substation control systems • Standard protection product offering on new GE generator installations Protection and Control As part of the UR family of Protection &Control devices, the G60 offers a high degree of modularity in its design and functionality, providing superior performance while meeting the toughest requirements of the marketplace. Advanced protection and control features of this relay includes: Generator Stator Differential High-speed stator differential protection provides sub-cycle detection and high-speed clearing of stator phase faults. Advanced CT saturation and failure detection algorithms maintain immunity to high current AC and low current DC saturation conditions that may occur due to external disturbances, such as transformer inrush or near generator faults, without sacrificing speed or sensitivity.

Key Benefits • Secure, high-speed protection elements for complete generator protection, compliant with IEEE® C37.102. extending asset life • Available Ethernet Global Data (EGD) to ease integration with new and existing GE control systems • Embedded Synchrophasor measurement capabilities (per IEEE® C37.118), eliminating the need for dedicated PMUs and support for synchrophasor multi-cast (per IEC® 61850-90-5) reducing bandwidth and communications infrastructure costs • Advanced IEC 61850 Ed. 2 implementation, complete settings via SCL files and IEC 61850-9-2 process bus solution enable resource and platform managing optimization and reduce cost of ownership • Increased network availability via failover time reduced to zero through IEC® 62439-3 “PRP” support • CyberSentry™ provides high-end cyber security aligned to industry standards and services (NERC® CIP, AAA, Radius, RBAC, Syslog) • Advanced fault and disturbance recording, including internal relay operating signals, eliminating the need for external recording devices

Overcurrent Elements The 889 can be used to provide backup protection for transformer and adjacent power system equipment. Instantaneous overcurrent (IOC) elements can be used for fast clearing of severe internal and external (through) faults. Up to six time overcurrent protection (TOC) elements per winding allow to coordinate with the adjacent protection zones and act as backup protection. • IOC protection functions are provided for phase, neutral & ground currents • TOC protection functions are provided for phase, neutral and ground currents. A variety of standard time curves including IEEE, IEC, GE Vernova IAC, I2t, definite time are provided • FlexCurves to coordinate with adjacent protections (including fuses) as well as transformer damage curves and thermal/ damage curves for downstream equipment Directional protection functions are provided for phase, neutral and ground currents. The voltage memory function enables a more reliable relay operation, especially for faults close to the VTs.

Out of Step Protection The out-of-step element provides out of step (loss-of-synchronism or pole slip) tripping function for generators. The element is simplified using a single blinder operating characteristic with an offset mho supervisory. It is easy to apply based on IEEE/ANSI C37.102 guidelines, and IEEE PES PSRC tutorial on generator protection. The purpose of the supervisory mho is to prevent operation on stable swings that pass through both blinders and outside the mho characteristic. In addition, the out-of-step tripping feature allows “MHO EXIT” trip mode to reduce stresses on the circuit breaker. Stator Thermal Protection The 889 provides thermal overload protection as per IEC 60255-8 to prevent generator damage caused by generator overheating. The 889 can be configured to trip the generator offline when the generator’s thermal limits are reached, or close an Alarm contact that signals operations personnel to take appropriate actions.

Sensitive Directional Power The 889 provides low forward power and reverse power elements to prevent generator motoring that can cause damage the prime mover. Independent settings for power pickup levels and operational delays are available for both alarming and tripping of each element. The 889 directional power element responds to three-phase directional power and is designed for reverse power (32REV) and low forward power (32FWD) applications for interconnections involving co-generation. Loss of Excitation Supporting application flexibility, the 889 offers two methodologies to support loss of excitation detection. This can be done through an impedance-based approach or a Reactive Power approach. Unlike the Impedance based function, the Reactive Power Function settings do not need machine parameters for setting and can be used in cases where machine parameters are not available.

100% Stator Ground Fault Protection The 889 provides 100% Stator Ground Fault Protection for High Resistance Grounded System (HRG), Low Resistance Grounded (LRG) or Hybrid Grounded Systems. For HRG systems the 889 employes a unique combination of Auxiliary Overvoltage and 3rd Harmonic Neutral Undervoltage protection elements to provide secure, reliable protection of the stator winding. With this function the 3rd harmonic neutral voltage variations do not need to be considered, simplifying the settings and configuration process. For LRG systems with parallel machines, the 889 provides ground fault coordination ensuring only the faulted generator is islanded. In Hybrid Grounded Systems, the 889 provides fast, dynamic switching from low-z to high-z when an internal generator fault is detected, reducing potential damage to the generator and eliminating the need for additional protection devices.

Overall Generator & Transformer Differential Protection The 889 provides overall generator and transformer differential protection (87O). It covers the protection zones from the generator neutral to the Generator Step-Up (GSU) Transformer’s High Voltage (HV) winding. For mid to large-size machines, the typical protection philosophy and architecture is to implement a dedicated transformer protection device along with a single function differential relay to provide the overall differential protection between the transformer and the generator. With support for 3 sets of phase CT inputs, the 889 can replace the single function device, providing the necessary overall differential protection with the added benefit of protection redundancy for both the Transformer and the Generator, when there is no tapping between the generator and GSU or unit transformer.

Generator Stator Differential The 889 provides fault clearing operation at up to sub-cycle speed, by utilizing a high-speed dual slope differential protection for detecting and clearing of stator phase faults. Advanced CT saturation detection algorithms maintain immunity to saturation conditions that may be caused due to external disturbances. Through the use of a directional check, additional supervision is provided to ensure the fault is internal to the generator before triggering it to trip. This sub-cycle operation translates to less burning, and hence low carbon dissipation and thermal stress on insulation. This also enables root cause analysis during diagnosis/maintenance of the winding (sever longer duration faults burns-out all the evidence and make root cause analysis extremely difficult or sometimes impossible).